Sezar vijiner sehrli kvadrat 4 uintsining ikkilangani

1 sezar
2 vijiner
3 sehrli kvadrat
4 uintsining ikkilangani
5 elgamal,
6 RSA,
7 Robin,
8 matritsa

Sezar shifri
Almashtirish usullari sifatida quydagi usullarni keltirish mumkin:
Sezar usuli, affin tizimidagi usuli, tayanch sozli Sezar usuli va boshqalar.
Sezar usuloda almashtiriluvchi harflar k soniga siljishi blan aniqlanadi. Yuliy Sezar bevosita k=3 bo’lganda ushbu usuldan foydalangan.
K=3 bo’lganda va alfavitdagi harflar m=26 ta bo’lganda quyidagi jadval hoil qilinadi
b
Masalan, matn sifatida KOMPYUTER sozini oladigan bo’lsak, Sezar usuli natijasida quyidagi shifrlangan yozuv hosol bo’ladi: C=NRPSBXWHU
Sezar usulining kamchiligi bu bir xil harflarning o’z navbatida, bir xil harflarga almashshidir.
Misol:
Bizga k-kalit, m-harflar soni, t-harflarnnig alfavidagi tartib raqami, x-shifrlangan harf, M-shifrlanuvchi so’z berilgan bo’lsin.
(t+k)mod m =x→ shifrlash formulasi
(x-k)mod m = t→ shifrni ochish formulasi
Shifrlash:
M=”doska”
K=3;
m=26

Mustaqil ish uchun misollar.
1. k=5, n=26: C=jsyjw, M=?
2. k=5, n=26: C=rtsnytw, M=?
3. k=5, n=26: C=xuehj, M=?
4. k=5, n=26: C=wzhmpe, M=?
5. k=5, n=26: C=vfqfr, M=?
6. k=6, n=26: C= ygrus, M=?
7. k=6, n=26: C= jkqgt, M=?
8. k=7, n=26: C= wypualy, M=?
9. k=7, n=26: C= uvrph, M=?
10. k=7, n=26: C= alslmvu, M=?
11. n=26: C=mjnad afxmds mjgvgyzuz smeaeukwadu zuetxmdu M=?
12. n=26: C=nkobebgk nisfvmyvt vfbknfvqntvk bmvetvkbyng M=?
13. n=26: C=olpcfchlojtgwnzwuwyohucfwmozofw M=?
14. n=26: C=pmqdgdiapgmxbdnphxpqhigpzibdsaapgx M=?
15. n=26: C= rkpyixdydwudwaefjqhgqbwqdkikbbqhy M=?
16. n=26: C=bizgkfcfxzprrjfjcrizrjfjzpkljyletyrcri M=?
17. n=26: C=sdygjalenscsdaldsjcjahlglarae M=?
18. n=26: C=lbffmk bdtezhkbmf etkhvabjdteb mebtezh kbmfetk M=?
19. n=26: C=elcjninurfcfufailcngrupzmctfcac M=?